Adjustable blind mechanism



Aug. 12, 1969 ABRAHAM 3,460,601

ADJUSTABLE BLIND MECHANISM Filed Nov. 1, 1967 4-Sheeis-Sheet I INVENTOR. GAR NE TT ABRAHAM Aug. 12, 1969 ABRAHAM ADJUSTABLE BLIND MECHANISM 4 Sheets-Sheet 2 mad Nov. 1. 19s? INVENTOR. GAR NETT ABRAHA Aug. 12, 1969 s. ABRAHAM 3,460,601

ADJUSTABLE BLIND MECHANISM Filed NOV. 1, 1967 4 Sheets-Sheet 5 I f I I I '1 i A9 k\\ \\\\i\ i 57 i L1 +1 3: 55

INVENTOR. GARNETT ABRAHAM Aug. 12,1969

Filed Nov. 1, 1967 a. ABRAHAM ADJUSTABLE BLIND MECHANISM 4' Sheets-Sheet 4 F/G.l2

JNVIJNTOR. GARNETT ABRAHAM United States Patent 3,460,601 ADJUSTABLE BLIND MECHANISM Garnett Abraham, 215 Manor Road, Staten Island, NY. 10314 Continuation-impart of application Ser. No. 610,071, Jan. 18, 1967. This application Nov. 1, 1967, Ser.

Int. Cl. E06b 9/322 US. Cl. 160-168 14 Claims ABSTRACT OF THE DISCLOSURE This is a continuation-in-part of application, Ser. No. 610,071, filed Jan. 18, 1967, now abandoned.

The present invention relates to Venetian blinds.

More specifically, the present invention relates to a blind having a simplified construction and embodying a novel arrangement of pulleys, cords and counterweights whereby the raising and lowering movement of the blind is accomplished with a minimum of manual effort.

Conventional types of Venetian blinds used for both commercial and residential applications have been found by both manufacturers and users to have several inherent disadvantages. Venetian blinds having wooden slats are are inherently heavy and require appreciable eifort to raise. Blinds having metal slats are somewhat easier to raise, but both types cause relatively heavy wear on the operating cords, the replacement of which is time-consuming and expensive. Cord wear results from cord movement in the cord passages and corners, and by the action of the cord latch which locks the blind into position.

Another source of trouble results from jamming of the cord in the latch mechanism, generally caused by the ratchet going beyond dead-center as blinds are lowered too rapidly. Another basic disadvantage of conventional blinds is that the control lines are constructed from cotton cord which has a short life after repeated use of the blind.

Accordingly, a Venetian blind mechanism is provided which overcomes all of the above-described disadvantages by utilizing a control cord coupled to one or more slotted ratchet pulleys for supporting the weight of the blind. The pulley are designed to rotate in one direction, preferably when the blind is raised. The pawls which are urged against the ratchet portion of the pulley prevent their rotation in the opposite direction, corresponding to the lowering of the blind.

In one embodiment, each of the pulleys contains an annular slot in its circumference having a width identical to the diameter of the control cord which is trunnioned in the slot. The cord is constructed from a multifibered, synthetic material and includes an external woven sheath which contains the plurality of fiber strands in a substantially circular cross-section. However, when the cord is bent around each of the ratchet pulleys and supports the weight of the blind, it has a tendency to flatten and become oval in cross-section so as to frictionally contract the walls of the slot in each of the pulleys. In order to counterbalance the tension in the lines created by the weight of the blind at one end, a suitable counterweight is connected to the opposite ends of the lines in order to mainice tain them in tension and in frictional contact with eac of the pulleys. By carefully dimensioning, the width c the slot in each of the pulleys, it has been found possibl to create a sufiicient amount of frictional drag betwee the cords in tension and the pulley to arrest the tendenc of the blind to open to its full length by the weight 0 its own slat members. The height of the blind may b then adjusted by merely relieving the tension in the cord by either lifting the counterweight, or the bottom of th blind, or by manually pulling down on the control lines In another embodiment, the ratchet pulley is provide with wedge-shaped inserts having fiat gripping edges fo frictionally retaining the cords of the blind in one POSllZlO] of the pulley. The wedge-shaped inserts form a V-shape crotch along the effective diameter of the drum of th pulley so that when the cords are trunnioned over th pulley in tension, the thin, flat edges of the inserts loc the cords in place and arrest the motion of the blind. I; a manner similar to the first embodiment, adjustments t the height of the blind can be: made by rotating th ratchet pulley one-half turn so that the inserts are momen tarily out of contact with the cords and the cords wil slip freely over its drum portion.

Therefore an object of the present invention is t provide a novel blind mechanism having a means of con trolling the height of a blind obviating the need for con ventional pull-cords and ratchet mechanisms usually em ployed for raising and lowering blinds of this type.

A still further object according to the invention is t provide a blind mechanism which may be raised 0 lowered by a light fingertouch control and which wil maintain its desired height after adjustment.

Another object according to the invention is to provid a blind mechanism which is simple in design, inexpensiv to manufacture, easy to assemble, and reliable in opera tion.

Other objects and features of the present inventio will become apparent from the following detailed de scription considered in connection with the accompany ing drawings, which disclose the embodiments of th present invention. It should be understood, however, the the drawings are designed for purposes of illustratio only, and not as a definition of the limits of the inven tion, as to which reference should be made to the a}; pended claims.

In the drawings, wherein similar reference character denote similar elements throughout the several views:

FIG. 1 is an elevation view of a Venetian blind accord ing to the invention.

FIG. 2 is an isometric diagram according to the in vention showing the arrangement of the control cord used in raising and lowering the blind.

FIG. 3 is a plan view of section 33 of FIG. 1, show ing the arrangement of pulleys and cords at the top 0 the blind.

FIG. 4 is a view of section 44 of FIG. 3 of on ratchet pulley, including a section of the control cord nc under tension.

FIG. 5 is a partial view of the same section 44 0 FIG. 3, showing the section of control cord as normall tensioned in service by the weight of the blind and count erweight.

FIG. 6 is a view of section 6-6 of FIG. 3, showing th pulley and cord arrangement at the top of one end 0 the blind.

FIG. 7 is a top plan view of another embodiment ac cording to the invention.

FIG. 8 is a front-plan view of the embodiment 0 FIG. 7.

FIG. 9 is a cross-sectional view along line 9-9 0 FIG. 7.

FIG. is an enlarged top-plan view of one end of lie apparatus of FIG. 7.

FIG. 11 is a cross-sectional view taken along line 111 of FIG. 10.

FIG. 12 is a cross-sectional view through line 12-12 -f FIG. 11.

FIG. 13 is a cross-sectional view similar to that of "1G. 11, showing the apparatus according to the invenion in a diiferent position; and

FIG. 14 is a side-plan view of a detail of FIGS. 11 nd 13.

Referring to FIG. 1, there is shown the Venetian blind ccording to the invention in a fully extended position. he blind includes a plurality of horizontally-spaced slats 5 supported in part by a pair of vertically extending, paced-apart tapes 16 adjacent to the ends of the slats. apes 16 are secured at one end to a bottom rail 18 thich forms the lowest slat of the blind mechanism.

The blind is also provided with an upper support memer 17 having a pair of hangers 37 depending its lower urface for pivotably supporting the uppermost slat 38. apes 16 are secured at their top to the ends of slat 38. apes 16 are constructed from conventional Venetian lind tape and include horizontally-spaced webs (not hown) which maintain the horizontal spacing of slats 5 as is well known in the art. Adjacent to each of ends 5 are a pair of control cords 19 which pass through oles formed in the ends of the slats. Cords 19 terminate 1 a loop surrounding bottom member 18 as indicated 1 FIG. 2.

Referring to FIG. 2 there is shown a pictorial arrange- ."tent of control cords 19 as coupled Within the blind iechanism according to the invention. The ends of cords 9 are terminated in a loop 31 around the end of bottom nember 18, said loop closing upon itself at binding porion 21. A collector pulley 23, having a central ratchet, utilized to collect cords 19. Pulley 23 is pivotably aounted at one end of support 17 by means of axle 39 nd includes a pair of annular slots 127 for receiving ords 19. The center portion of pulley 23 also includes ratchet surface having stops 140 and a pawl 128 urged hereagainst (FIGS. 3 and 6). Pawl 128 is demountably oupled to support 17 by pins 129. The ratchet of pulley v3 permits rotation in only the clockwise direction.

Each of cords 19 is trunnioned around a correspond 1g ratchet pulley 24 and collected at one end of the blind y pulley 23. Cords 19 are joined integrally at their colacted end of the blind to form a drawstring. A counterveight 20 is fastened through ring 22 to the drawstring ortion of cords 19 to provide tension to the cords at all lmes.

Referring particularly to FIG. 3, a plan view of the .ppermost support member 17 is shown illustrating in etail the arrangement of contol cords 19. Support memer 17 includes a channel 32 cut along its length to conain one extension of cord 19. Channel 32 includes a lurality of guides disposed along its length to mainain the cord within the channel. At each end of member 7 cord 19 is trunnioned around pulley 24 and collected y pulley 23 at a common end of the blind. The control ord coming from the opposite end of the blind is offset t a slight angle prior to its point of collection around ulley 23. This permits the collection of cords 19 to take lace toward the front portion at one end of support 17 J as to make the drawstring readily accessible to the ser.

Referring to FIGS. 46, pulley 24 is shown pivotably ipported within member 17 on axle 38. Cut through the enter portion of pulley 24 is an annular slot 27 having substantially rectangular cross-section. The widths of 0t 27 as well as slot 127 are designed approximately qual to the diameter of cord 19. The circumference of ulleys 24 consists of a ratchet wheel having a plurality f stops for engaging pawl 28 in contact therewith. awl 28 is detnountably coupled to support member 17 y means of fasteners 29 so as to permit pawl 28 to pivot when pulley 24 is rotated clockwise. The center portion of the engaging edge of pawl 28 is hollowed out to permit cord 19 to pass therethrough.

Cord 19 is constructed from a plurality of individually disposed center strands 25 surrounded by a woven fabric sheath 34. Strands 25 are made from a resilient synthetic fiber such as nylon, Dacron, and the like, and resist permanent deformation. Strands 25 are spirally wound within sheath 34 so that the cross-sectional profile of cord 19 remains substantially circular when no tension is applied thereto. However, due to the weight of the blind on one end of cords 19, and the pull of counterweight 20 at their opposite end, cords 19 are stressed in tension over pulleys 23 and 24 and in particular on the circumferential seat of slots 127 and 27. This causes cord 19 to flatten in the slots and assume an oval configuration, as shown in FIG. 5, so that its fabric sheath 34 becomes urged frictionally against the sidewalls of slots. The frictional contact of cord 19 with respect to each pulley extends over an angular segment of approximately This frictional drag, together with the counterbalancing elfects of counterweight 20, is sufficient to offset the weight of slats 15 which gather against bottom support member 18 for any height setting of the blind.

When the blind, according to the invention, is fully extended, tapes 16 support the weight of slats 15 so that counterweight 20 need only have a weight equal to, or less than, the weight of the bottom member 18. When the blind is raised by either pulling manually downward on counterweight 20, or lifting bottom support 18 upward, pulleys 23 and 24 rotate clockwise. As the bottom portion of tapes 16 begins to pleat to permit slats 15 to gather against bottom member 18, the tension in cords 19 increases by the amount of the additional weight of slats 15 against the bottom member 18. When the blind is released at its new height position, pulleys 23 and 24 rotate momentarily counter-clockwise until one of stops and 40 engage the leading surface of pawls 128 and 28 respectively, and become locked thereagainst. The tension in lines 19 produced by the suspended weight of the blind and counterweight 20 causes cord 19 to flatten within slots 127 and 27 as shown in FIG. 5, and thus frictionally bind against the walls of the slot to prevent further downward movement of the blind. It is also possible to install a small spring in front of pulley 24 in order to aid in raising cord 19 out of slots 127 and 27 when the blind is raised from the bottom rail.

In order to lower the blind, it is only necessary to lift counterweight 20 sufficiently to relieve the tension in line 19 so as to permit resilient strands 25, within the cord, to assume their original shape, as shown in FIG. 4, and permit cord 19 to slide freely within slots 127 and 27. The blind will resume a stable new position when tension is applied to cord 19. The blind may also be lowered by manually pulling downward on bottom rail 18 with a force suflicient to overcome the frictional drag on cords 19 induced by slots 127 and 27. For Venetian blinds having longer slats, it is customary to employ a center tape as well as a control cord secured to the center of bottom support 18. In this manner, a third pulley (not shown) may be pivotably supported at the center of upper support member 17 forming a duplication of the ratchet pulley assembly described herein. The center control cord may be collected on ratchet pulley 23 in a manner identical to that described for the first two control cords and coupled to counterweight 20 at the intersection of the first two control cords.

Referring to FIGS. 7 and 8, there is shown an adjustable blind mechanism which includes a box frame 51 for supporting the blind between opposing sides of window frame 50. The mechanism of this embodiment includes an extending portion 55 secured at one end of box frame 51 for containing the adjusting controls of the blind.

Referring to FIGS. 9 and 10, there is shown in detail one of the idler pulleys 52 pivoted through axle 53 on stand 49. Stand 49 is secured on the floor of box frame 51 over aperture 48 to permit idler pulley 52 to collect and distribute cord 19 through corresponding apertures in slats 15, supported between tapes 16. Cord 19 can be conventional blind cord for this embodiment of the blind. The other portion of cord 19, shown extending beyond idler wheel 52, is connected to a similar idler pulley (or pulleys) along the center or opposite end of the blind in a manner similar to that shown with respect to the first embodiment. Both portions of cord 19 are collected over a double ratchet pulley 54, pivotably mounted in extending frame 55 by means of axle 58.

Referring now to FIGS. 11-14, there is shown in detail the applicaton of ratchet wheel 54 t the adjustable blind mechanism of this embodiment. Along one edge of the circumference of pulley 54 is included a pair of rectangular slots 62, positioned diametrically opposite to one another. Slots 62 are adapted to engage the leading edge 61 of pawl 56. Pawl 56 is pivotably supported against one wall of extending frame 55 as shown in detail in FIG. 14. Pawl 56 is urged downward against the circumference of pulley 54 either by gravity, or by a spring (not shown),

so that it is in continuous engagement with pulley 54.

The effective diameter 59 of ratchet pulley 54 as shown in broken line, has been relieved along one side to permit the insertion of V-shaped wedge pieces 57 into the drum of pulley 54. Wedge pieces 57 are constructed, for example, from thin gauge metal, is tapered in width so that its flat edges and projecting base portion 57a will grip cord 19 from three sides at the effective diameter 59 of pulley 54. The free ends of cord 19 are terminated at knot 19a in a bell-shaped counterweight 120. Counterweight 120 operates similar to that of the embodiment described with respect to FIGS. l-6 and provides tension in cords 19 so that they will be urged against the flat edges of wedge-shaped pieces 57 as shown in detail in FIGS. 11 and 12. Wedge shaped pieces 57 serve most effectively as a stop for cords 19 when they are positioned along the approximate 90 degrees arc-of-contact of the effective diameter 59 of pulley 54. At least one of the stops 62 is positioned on the circumference of wheel 54 to permit wedge shaped pieces 57 to engage and secure cords 19. A second notch 62, positioned along the circumferences of pulley 54, contacts pawl 56 so that wedge shaped pieces 57 will be out of engagement with cords 19 as shown in FIG. 13.

The adjustable blind according to this embodiment opcrates as follows:

In order to raise the blind, the user pulls down on counterweight 120, connected to cords 19, so as to cause ratchet wheel 54 to rotate clockwise and collect cords 19. When the desired height of the blind has been reached, the user will release counterweight 120. The weight of the blind mechanism as applied to cords 19 will cause pulley 54 to rotate counter-clockwise until pawl 56 engages one of the slots 62. If pulley 54 comes to rest in the position as shown in FIG. 11, the flat edges of wedge-pieces 57 will grip cords 19 and prevent further movement. If pulley 54 comes to rest in the position as shown in FIG. 13, the user need only pull downward on cords 19 until ratchet pulley 54 rotates 180 degrees to assume its position as shown in FIG. 11.

It is obvious, then, that in order to lower the blind mechanism, the user can pull downward on cords 19 until pulley 54 rotates 180 degrees into its position as shown in FIG. 13, so that the cords will be released from wedge-shaped pieces 57 and slide freely through the drum of the pulley. By lifting upward on counterweight 120, and utilizing the weight of the blind, cords 19 will slip freely over the drum of pulley 54 until the desired position of the blind is reached. The user may then lock the blind into its new position by pulling downward on cords 19 until wheel 54 assumes its locking position as shown in FIG. 11. The mass of counterweight 1220 need only be designed to have a magnitude to apply a suflicient amount of tension to cords 19 with respect to the edge of the wedge shaped pieces 57 so that the edges will gri the cords to maintain the blind mechanism in its desire position. When the blind mechanism is initially secure to window frame 50, and after the blind is opened ant extended down to cover the full leigth of the frame counterweight can be slid along cords 19 and SBCIlIfit in place at the top of the blind, adjacent to frame 50 by tying knot 19a underneath the bell of the weight.

The blind mechanism according to this embodimen may also be raised or lowered by lifting upward or pullin; downward on base 18 at the bottom of the blind so tha ratchet pulley 54 will rotate freely clue to the tensiol applied by counterweight 120.

The blind mechanism according to the invention ma: also be used to raise and lower drapery fabrics, accordio1 pleated shades of plastic or wood, and the like. In thi arrangement a tubular support rail may be employed tr support the control cords for adjusting the height of tht blind.

While only a few embodiments of the present inven tion have been shown and described, it will be understoor that many changes and modifications may be made there in without departing from the spirit and scope of tilt invention as defined by the appended claims.

What is claimed is:

1. An adjustable blind mechanism comprising;

a horizontal support member,

a blind depending said support member,

a plurality of control cords secured at one end of sait blind,

at least one ratchet pulley wheel pivotably supporter within said support member and positioned to re ceive the opposite end of said control cord, sair wheel having at least one stop disposed along it: circumference,

a releasable pawl urged against the circumference 0: said wheel for contact with said stop to permit rota tion of the wheel in a single direction, and

means coupled within said ratchet pulley for releasabl retaining said control cords when stressed in tensior after adjustment of said blind mechanism.

2. The mechanism as recited in claim 1 wherein eacl of said control cords comprises a plurality of resilien strands, and an external sheath surrounding said strand: for maintaining said cord in a circular cross-section wher not in tension.

3. The mechanism as recited in claim 2 wherein saic means coupled to said pulley comprises annular slo means disposed within the circumference of said whee for receiving said cords and having a width and deptl approximately equal to the circuit diameter of said non tensioned cord.

4. The mechanism as recited in claim 3 additionally comprising a second ratchet pulley pivotably secured tr one end of said support member and having a plurality of said annular slots for collecting said control cords.

5. The mechanism as recited in claim 4 additionally comprising a counterweight fastened to the collected end: of said control cords, said counterweight having a mass sufficient to pretension and deform the control cord trun nioned in said slot means so that said external sheath is frictionally urged against the walls of said slot means for retaining the cord therein when said blind is adjusted tc any predetermined height.

6. The mechanism as recited in claim 5 wherein tht stops of said pulley means are directed against said paw to inhibit rotation thereof when said blind is lowered.

7. The mechanism as recited in claim 6 wherein saic control cord is slideably engaged to said pulley slot mean. when the tension in said cord is relieved so as to permit said blind to be lowered.

8. The mechanism as recited in claim 7 wherein saic blind comprises a Venetian blind.

9. The mechanism as recited in claim 1 wherein said means coupled to said pulley comprises V-shaped wedgeneans inserted across the openings of said pulley parallel 0 its axis, said wedge means having thin edges forming :onstricted passageways to grip said cord under tension.

10. The mechanism as recited in claim 9 wherein said u11ey comprises one stop to position said wedge-means lCI'OSS the path of and in contact with said control cords,

and at least a second stop to position said wedge-means out of engagement with said cords to permit said cords to slide freely over the drum of said pulley means.

11. The mechanism as recited in claim 10 wherein said sledge-means additionally comprises an upstanding proection integrally formed at its base for contact with said ords.

12. The mechanism as recited in claim 11 additionally :omprising an extension frame secured to one end of aid support member for containing and supporting said aawl and ratchet pulley.

References Cited UNITED STATES PATENTS 444,302 1/1891 Niss 160-172 450,392 4/1891 Wilson. 1,022,415 4/1912 Hannan. 2,386,695 10/1945 Lester-Torsen 160-172 2,594,637 4/1952 Gertzon 160168 PETER M. CAUN, Primary Examiner 

